Classification
304 - Factors affecting social behavior
610 - Medicine & health
90
330 - Economics
38
333 - Economics of land & energy
23
320 - Political science
20
370 - Education
15
600 - Technology
9
363 - Other social problems & services
4
380 - Commerce, communications & transportation
4
336 - Public finance
1
630 - Agriculture & related technologies
1